Due to the limited self-repair capacity of cartilage, regenerative medicine therapies for the treatment
of cartilage defects must use a significant amount of cells, preferably applied using a hydrogel system
that can promise their delivery and functionality at the specific site. This paper discusses the potential
use of k-carrageenan hydrogels for the delivery of stem cells obt ained from adipose tissue in the
treatment of cartilage tissue defects. The developed hydrogels were produced by an ionotropic
gelation met hod and human adipose stem cells (hASCs) were encapsulated in 1.5% w/v k-carrageenan
solution at a cell density of 5 10
6
cells/ml. The results from the analysis of the cell-encapsulating
hydrogels, cultured for up to 21 days, indicated that k-carrageenan hydrogels support the viability,
proliferation and chondrogenic differentiation of hASCs. Additionally, the mec hanical analysis
demonstrated an increase in stiffness and viscoelastic properties of k-carrageenan gels with their
encapsulated cells with increasing time in culture with chondrogenic medium. These results allowed
the conclusion that k-carrageenan exhibits properties t hat enable the in vitro functionality of
encapsulated hASCs and thus may provide the basis for new successful approaches for the treatment
of cartilage defects.Elena G. Popa would like to acknowledge the Portuguese Foundation for Science and Technology (PhD Grant No. SFRH/BD/64070/2009)
